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Chapter 25: Electric Current and Direct Current Circuits

Chapter 25: Electric Current and Direct Current Circuits. Section 25-3: Energy in Electric Circuits.

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Chapter 25: Electric Current and Direct Current Circuits

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  1. Chapter 25: Electric Current and Direct Current Circuits Section 25-3: Energy in Electric Circuits

  2. An energy efficient light bulb uses 15 W of power for an equivalent light output of a 60 W incandescent light bulb. If you use the light an average of 6 hours per day, how much money do you save each year by using the energy efficient light bulb instead of the incandescent light bulb? Assume that 1 kWhr costs 14 cents. • $4.75 • $9.25 • $18.37 • $6.94 • $13.80

  3. An energy efficient light bulb uses 15 W of power for an equivalent light output of a 60 W incandescent light bulb. If you use the light an average of 6 hours per day, how much money do you save each year by using the energy efficient light bulb instead of the incandescent light bulb? Assume that 1 kWhr costs 14 cents. • $4.75 • $9.25 • $18.37 • $6.94 • $13.80

  4. A comparison of the power losses (P1, P2, or P3) in the resistors of the circuit in the diagram shows that, if R1 = R2 = R3, • 4P1 = P2 = P3 • P1 = 2P2 + 2P3 • P1 = P2 = P3 • P1 = (1/2)P2 = (1/2)P3 • P1 = P2 + P3

  5. A comparison of the power losses (P1, P2, or P3) in the resistors of the circuit in the diagram shows that, if R1 = R2 = R3, • 4P1 = P2 = P3 • P1 = 2P2 + 2P3 • P1 = P2 = P3 • P1 = (1/2)P2 = (1/2)P3 • P1 = P2 + P3

  6. Two resistors are connected in series across a potential difference. If the current carried by resistor A is I, what is the current carried by B? • I • 2I • I/2 • 4I • impossible to determine unless more is known about the resistances of A and B

  7. Two resistors are connected in series across a potential difference. If the current carried by resistor A is I, what is the current carried by B? • I • 2I • I/2 • 4I • impossible to determine unless more is known about the resistances of A and B

  8. Four identical light bulbs are connected to a power supply as shown. Which light bulb consumes the most power? • B1 • B2 • B3 • B4 • They all consume the same amount of power.

  9. Four identical light bulbs are connected to a power supply as shown. Which light bulb consumes the most power? • B1 • B2 • B3 • B4 • They all consume the same amount of power.

  10. Four identical light bulbs are connected to a power supply as shown. Which light bulb consumes the most power? • B1 • B2 • B3 • B4 • They all consume the same amount of power.

  11. Four identical light bulbs are connected to a power supply as shown. Which light bulb consumes the most power? • B1 • B2 • B3 • B4 • They all consume the same amount of power.

  12. Three identical light bulbs are connected in parallel to a constant voltage power supply. Initially, switch S1 is closed and the other two switches open. When the other two switches, S2 and S3, are closed, the brightness of the first light bulb • is dimmer. • is unchanged. • is brighter.

  13. Three identical light bulbs are connected in parallel to a constant voltage power supply. Initially, switch S1 is closed and the other two switches open. When the other two switches, S2 and S3, are closed, the brightness of the first light bulb • is dimmer. • is unchanged. • is brighter.

  14. The diagrams are schematic of a battery connected to a light bulb with a switch. When the switch is closed, which light bulb will come on? • 1 • 2 • 3 • 4 • All of them.

  15. The diagrams are schematic of a battery connected to a light bulb with a switch. When the switch is closed, which light bulb will come on? • 1 • 2 • 3 • 4 • All of them.

  16. Which of the schematic below best represents the circuit? • 1 • 2 • 3 • 4 • None of them.

  17. Which of the schematic below best represents the circuit? • 1 • 2 • 3 • 4 • None of them.

  18. If two elements of a circuit are in parallel, they must have the same • charge. • potential difference across them. • resistance. • potential difference across them and the same current. • current.

  19. If two elements of a circuit are in parallel, they must have the same • charge. • potential difference across them. • resistance. • potential difference across them and the same current. • current.

  20. Which of the following relations among the quantities in the figure is generally correct? • I1R1 = I2R2 • I3R3 = I4R4 • I1R1 = I4R4 • I3R4 = I4R3 • I1R1 + I2R2 = e

  21. Which of the following relations among the quantities in the figure is generally correct? • I1R1 = I2R2 • I3R3 = I4R4 • I1R1 = I4R4 • I3R4 = I4R3 • I1R1 + I2R2 = e

  22. Three resistors are placed in a simple circuit. In which of the various configurations shown do all three resistors carry the same current?

  23. Three resistors are placed in a simple circuit. In which of the various configurations shown do all three resistors carry the same current?

  24. Chapter 25: Electric Current and Direct Current Circuits Section 25-5: Kirchhoff’s Rules

  25. The power delivered by the battery in the circuit shown is • 2.5 W • 7.0 W • 3.1 W • 9.7 W • 5.3 W

  26. The power delivered by the battery in the circuit shown is • 2.5 W • 7.0 W • 3.1 W • 9.7 W • 5.3 W

  27. The circuit in the figure contains a cell of emf e and four resistors connected as shown. Let the currents in the resistors R1, R2, R3, R4, be designated by I1, I2, I3, I4, respectively. Which of the following equations is necessarily correct? • I1 = I2 • I2 = I3 • I3 = I4 • I1 = I4 • I1 = I2 + I3

  28. The circuit in the figure contains a cell of emf e and four resistors connected as shown. Let the currents in the resistors R1, R2, R3, R4, be designated by I1, I2, I3, I4, respectively. Which of the following equations is necessarily correct? • I1 = I2 • I2 = I3 • I3 = I4 • I1 = I4 • I1 = I2 + I3

  29. You want to measure the current through and the voltage difference across a resistor. How should you connect the ammeter and voltmeter to the resistor? • Connect both meters in parallel. • Connect both meters in series. • You should connect the ammeter in parallel and the voltmeter in series. • You should connect the ammeter in series and the voltmeter in parallel. • It does not matter how you connect the meters to the resistor.

  30. You want to measure the current through and the voltage difference across a resistor. How should you connect the ammeter and voltmeter to the resistor? • Connect both meters in parallel. • Connect both meters in series. • You should connect the ammeter in parallel and the voltmeter in series. • You should connect the ammeter in series and the voltmeter in parallel. • It does not matter how you connect the meters to the resistor.

  31. The particle in the figure is positively charged. is negatively charged. could be negatively or positively charged.

  32. The particle in the figure is positively charged. is negatively charged. could be negatively or positively charged.

  33. The left diagram shows a positively charged particle is moving with velocity v in a magnetic field B. Using the arrows in the right diagram, what is the direction of the magnetic force on the particle?

  34. The left diagram shows a positively charged particle is moving with velocity v in a magnetic field B. Using the arrows in the right diagram, what is the direction of the magnetic force on the particle?

  35. The left diagram shows a force F on a negatively charged particle moving a magnetic field B. Using the arrows in the right diagram, what is the direction of the velocity of the particle?

  36. The left diagram shows a force F on a negatively charged particle moving a magnetic field B. Using the arrows in the right diagram, what is the direction of the velocity of the particle?

  37. If the magnetic field vector is directed toward the north and a positively charged particle is moving toward the east, what is the direction of the magnetic force on the particle? up west south down east

  38. If the magnetic field vector is directed toward the north and a positively charged particle is moving toward the east, what is the direction of the magnetic force on the particle? up west south down east

  39. The SI unit of magnetic field is the tesla (T). This is equivalent to N · s/(C · m) N · C/(s · m) N · m/s2 C/(A · s) None of these is correct.

  40. The SI unit of magnetic field is the tesla (T). This is equivalent to N · s/(C · m) N · C/(s · m) N · m/s2 C/(A · s) None of these is correct.

  41. An electron is traveling horizontally east in the magnetic field of the earth near the equator. The direction of the force on the electron is zero north south upward downward

  42. An electron is traveling horizontally east in the magnetic field of the earth near the equator. The direction of the force on the electron is zero north south upward downward

  43. Electrons travel at an initial velocity v0. They pass through a set of deflection plates, between which there exists an electric field which deflects them upwards toward point b. In which direction should a magnetic field be applied so that the electrons land undeflected at a?

  44. Electrons travel at an initial velocity v0. They pass through a set of deflection plates, between which there exists an electric field which deflects them upwards toward point b. In which direction should a magnetic field be applied so that the electrons land undeflected at a?

  45. All of the charged particles that pass through a certain set of crossed electric and magnetic fields without deflection must have the same mass. speed. momentum. energy. charge-to-mass ratio.

  46. All of the charged particles that pass through a certain set of crossed electric and magnetic fields without deflection must have the same mass. speed. momentum. energy. charge-to-mass ratio.

  47. A uniform magnetic field is parallel to and in the direction of the positive z axis. For an electron to enter this field and not be deflected by the field, the electron must be traveling in which direction? any direction as long as it is in the xy plane. any direction as long as it is in the xz plane. along the x axis. along the y axis. along the z axis.

  48. A uniform magnetic field is parallel to and in the direction of the positive z axis. For an electron to enter this field and not be deflected by the field, the electron must be traveling in which direction? any direction as long as it is in the xy plane. any direction as long as it is in the xz plane. along the x axis. along the y axis. along the z axis.

  49. The top diagram shows the velocity of a positively charged particle. Which arrow best represents the direction of the magnetic field due to the moving charge at r ?

  50. The top diagram shows the velocity of a positively charged particle. Which arrow best represents the direction of the magnetic field due to the moving charge at r ?

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